In the field of agriculture, various devices for attaching sheets of material are known. The prior art contains devices made of wood and aluminum that attach plastic sheets covering agricultural hothouses or greenhouses. One attachment device consists of a wooden pole upon which the plastic sheet is rolled. In order to attach the sheet, nails are inserted in the plastic sheet to attach it to the wooden rod.
In addition, attachment devices made of aluminum are also known. These aluminum attachment devices are based on the passive operation of placing a male and female component on one another. The sheet is attached by spreading the sheet on the female part, placing the male part on the female part, and subsequently attaching a clip that prevents the two parts from separating.
These devices have many disadvantages. The attachment devices made of wood are problematic because the method of attaching the plastic sheets by inserting nails through the sheet causes damage to the plastic sheets. These devices can only be used once, thereby preventing the reuse or adjustment of sheets. In addition, because of the aggressive method of attachment, it is not possible to use the wooden device for attaching sheets made of delicate materials, such as paper. Utilizing this method, delicate materials would tear.
Aluminum attachment devices in the prior art are also problematic because the plastic sheets are only passively attached. In these passive attachment devices, the two parts of the device, one on the other with the sheet between them, only have a clip holding them together. This method of attachment frequently causes the sheet to be cut in the place of attachment to the attachment device, and thus causes damage to the sheet and the loss of attachment and tension of the sheet. In addition, the metal clips tend to come loose and thus release the attachment of the sheet. It is therefore necessary to fit numerous metal clips and to check them frequently in order to verify that they remain in place.
None of the above types of devices provide the possibility of initial locking or temporary attachment of the sheets. Rather the prior art only allows for final attachment and fitting. This causes great difficulties when covering hothouses, stretching the sheets, and adjusting and correcting them as necessary.
In addition, the prior art does not account for drainage of the condensation water. In agricultural hothouses in which there is a system for controlling the irrigation and the climate inside them, condensation water typically accumulates in random places in the roof of the hothouse and drips on the plants. This affects the monitoring and control of the climate and the irrigation in the hothouse. Further, the condensation water dripping downwards may produce various diseases in the plants. Consequently, it would be desirable to provide a way to collect and drain the accumulated condensation water.
Further, these devices do not have the shape of an angle, and the constructor must therefore attach angles to produce a frame for the structure. It would therefore also be desirable to utilize a device for attaching sheets that is already angled to produce a frame.
There is a need for an efficient device that will produce active and strong locking of sheets, including plastic sheets for hothouses, capable of multiple uses, i.e., the ability to remove and attach sheets again and again without damaging them. In addition there is also a need for a device that collects the condensation water accumulating mainly in the roof of the hothouse. Further, it would be beneficial to integrate an angle support into the design of the aforementioned devices.